<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>01-transition</title>
    <style>
      #one {
        width: 50px;
        height: 50px;
        background-color: orange;
        transition: width 1s, background 2s;
        transition-delay: 1s;
        /* transition-duration:  */
      }
      #one:hover {
        width: 500px;
        background: blue;
      }
    </style>
  </head>
  <body>
    <div id="one"></div>
  </body>
</html>
